Auto-Analysis for Ki-67 Indices of Breast Cancer Using Specified Computer Software and a Virtual Microscopy
Pages 73-78
Kazuya Kuraoka, Kiyomi Taniyama, Miho Tanaka, Yukari Nakagawa, Naoko Yasumura, Tamaki Toda, Mikie Shitaune, Akihisa Saito, Junichi Sakane, Yoko Kodama, Toshinao Nishimura, Nao Morii, Hirotoshi Takahashi and Hiroyasu Yamashiro

DOI: http://dx.doi.org/10.6000/1927-7229.2014.03.02.3
Published: 30 April 2014

Abstract: Ki-67 index is one of important markers that is correlated with chemotherapy response and prognosis of breast cancer patients. However, Ki-67 index is not easily provided and are limited by intra-observer error and potentially subjective decision making. We performed this study to develop an objective auto-analysis system to count Ki-67 indices. A total of185 invasive breast cancer cases were used. Immunohistochemical staining was performed using auto-stainer and MIB-1 antibody. The results were stored digitally by virtual microscopy and auto-analyzed by Genie/Aperio software (Vista, CA, USA). As for Ki-67 indices, a good correlation was observed between direct ocular observations and auto-analysis techniques (r = 0.94, p < 0.001). The index examined by auto-analysis was significantly correlated with nuclear atypia, mitotic counts, and nuclear grade of pT1 breast cancers. Auto-analysis of 5 high power fields was better correlated with nuclear grade than that of whole fields. Further, the Ki-67 index was better correlated with mitotic counts than with nuclear atypia.Auto-analysis can provide results concordant with those obtained by direct ocular observation in a short time. Auto-analysis is more likely to result in an objective observation and provide a means by which to standardize methods for immunohistochemical Ki-67 indices of breast cancer.

Keywords: Breast cancer, Ki-67, auto-analysis, virtual microscopy, immunohistochemistry, prognosis, objective analysis, nuclear grade.